Objective: To study the influence of siRNA targeting survivin  on chemotherapy sensitivity of HCC cells.
Methods: siRNA eukaryotic expression vector was generated. After the vector stablely transfected into HepG2 cells, the effects of chemotherapy drugs on HCC cells were observed.
Results: The recombinant plasmid Psilence(+)-survivin was successfully constructed. Survivin mRNA expression inhibition ratio reached 73% detected by RT-PCR. MTT methods detected that siRNA treated HCC cells were affected by MCC, the survival rate of HepG2, HepG2/Silence(-) cells was inhibited only at 48 h (0.505±0.015) compared to control groups untreated with MCC（0.824±0.322）(P＜0.05). When the survivin gene was inhibited, the survival rate of the HepG2/Silence(+) cells(0.520±0.017）was inhibited at 12 h compared to control groups(0.741±0.005) and reached peak at 48 h (P＜0.05). The Westen-blot detection indicated that OD value of survivin protein expression in untreated with MMC was 3 4273±323 and decreased to 2 1415±142, 1 6771±122, 1 3672±133 at 12 h, 24 h and 48 h after treated with MMC, the difference was significant(P＜0.05). The apoptosis ratio of HepG2/Silence(+)＋MMC groups at 12 h, 24 h and 48 h increased significantly compared to control groups.The caspase-3 activity detection indicated that the caspase-3 activity in HepG2/Silence(+) cells treated with MMC at 12h, 24h and 48 h was 0.19±0.05, 0.33±0.12, 3.79±0.27, 9.34±0.86 respectively, and the difference between the all time points were significant (all P＜0.05).
Conclusions: The siRNA targeting survivin can not only suppress the expression of survivin in HCC cells, but can also enhance the chemotherapy sensitivity. This effect is accomplished by enhancing the caspase-3 activity and increasing the apoptosis ratio in HCC cells.